Protective effect of flunarizine and nifedipine alone and in combination with anticonvulsant drugs against PTZ-induced seizures in mice

Abstract

The anticonvulsant effect of flunarizine has been compared to that of nifedipine in the pentylenetetrazole (PTZ)-induced seizure incidence/latency test and the PTZ seizure threshold test in mice. Nifedipine was found to have anticonvulsant activity in both models but flunarizine only had an anticonvulsant effect in the PTZ seizure incidence/latency test. Interactions with commonly used anti-epileptic drugs were also examined. In both models, the anticonvulsant effects of small doses or carbamazepine and phenytoin were enhanced by flunarizine and the effects of small doses of ethosuximide were enhanced by nifedipine. The effects of large doses of the anti-epileptic drugs were not further enhanced by either flunarizine or nifedipine. It is possible that these findings in mice are relevant to the variability of the responses to calcium antagonists as add-on therapy for epilepsy in man.